The goal of this project is to develop a realistic conductance-based network model of retinogeniculate transmission by the dorsal lateral geniculate nucleus (dLGN) and perigeniculate nucleus (PGN) of the cat. Previous theoretical work by my sponsor, John Rinzel (Center for Neural Science and Courant Institute for Mathematical Sciences, NYU) has elucidated the role of the low-threshold Ca2+ conductance (IT), GABA- ergic inhibition, and the post-inhibitory rebound (PIR) properties of thalamocortical (TC) and nuclear reticularis thalami (RE) neurons in the generation of rhythmic bursts of action potentials (APs) and the lurching propagation of spindle waves in the "sleeping" thalamic slice preparation. We will wake up" this thalamic slice model by tuning a parameter representing cholinergic neuromodulation and test two specific hypotheses regarding sensory gating by dLGN: 1) that transient bursts of APs fired by TC neurons can be stimulus driven and signal novelty detection in addition to functional disconnect of the thalamic gate, and 2) that control of local inhibitory RE neuron responsiveness can have functional consequences on the receptive field properties of TC neurons and, consequently, the filter properties of the dLGN. Predictions of the model will be tested in the laboratory of vision researcher S. Murray Sherman (SUNY, Stony Brook).